Trifluoroacetic acid → HCID 178523578, compound

Participants

Reaction Steps

A solution of phenylchloroformate (0.045 ml, 0.36 mmol), triethylamine (0.085 ml), 4-dimethylaminopyridine (catalytic) and trans-4(2,4-bis{[tert-butyl(dimethyl)silyl]oxy}phenyl) cyclohexylamine (0.043 g) in dichloroethane (11 ml) was stirred at room temperature for 60 hr. The mixture was partitioned between saturated aqueous sodium carbonate (15 ml) and dichloromethane (15 ml). The aqueous phase was extracted with dichloromethane (2×15 ml) and the combined organic extracts washed with brine (20 ml), dried over magnesium sulfate, filtered and concentrated in vacuo. Purification via flash chromatography (SiO2, ethyl acetate/petroleum ether) afforded a colourless gum. This was dissolved in dichloromethane (15 ml) and warmed with a mixture of water (7.5 ml) and trifluoroacetic acid (7.5 ml) at 80° C. for 17 hr. On cooling, toluene (25 ml) was added and the solution concentrated in vacuo. Methanol (25 ml) was added and the solution again concentrated in vacuo. Purification via flash chromatography (SiO2, ethyl acetate/petroleum ether) afforded the title compound (0.013 g, 13%) as a colourless solid. δH (CD3OD) 1.44-1.63 (4H, m), 1.96 (2H, m), 2.13 (2H, m), 2.86 (1H, m), 3.55 (1H, m), 6.30 (2H, m), 6.92 (1H, d), 7.12 (2H, m), 7.22 (1H, m) and 7.40 (2H, m); m/s(ES+) 328.26 (M+H)+.

Provenance & Evidence